Assessment of N2O generation during NH3 biofiltration of piggery air

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AMMONIA AND GREENHOUSE GAS EMISSIONS IN PIG FATTENING ON SLATTED FLOOR WITH EXCREMENT DISCHARGE BY FLAT SCRAPING

Gas emissions (NH 3 GHG) from four pig fattening rooms on slatted flooring with flat scraping and under-floor air evac uation were measured in three consecutive batches between May 2009 and June 2010 i n the experimental station of Crecom (France). Gas concentrations and ventilation rates were measured and recorded during 3 periods of 14 days during the bre eding period (day 7 to 21, 35 to 49 and 63 to 77). Gas concentrations were measured with a n infrared photoacoustic monitor (INNOVA 1412) in the room area. Manure was scrap ed once a day and stored in the breeding rooms for two weeks. Measured carbon emissions (C-CH 4 and C-CO 2 ) were validated by comparison with the C mass balanc e deficit, whereas measured nitrogen emissions (N- NH 3 and N-N 2 O) were not validated by comparison with the N mass balance deficit. Observed differences between measurement and mass balance deficits were explained by the samplin g point site for concentration measurements that was not representative of the exha ust air. With additional experiments, we demonstrated that ammonia concentrat ions measured in the exhausted air were 51 % higher than those measured in the room. Under-floor air evacuation combined with a flat scraper system enabl ed the reduction of ammonia concentrations in the room and improved air quality and the working environment. However, compared to a slurry storage system, a flat scraper system with manure stored in the room after scraping, reduces GHG emiss ions (N 2 O and CH 4 ) in the exhaust air, but can increase NH 3 emissions

Greenhouse gas emissions during ammonia biofiltration of piggery air: a case study

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NH3 biofiltration of piggery air

International audienceAn aboveground pilot-scale biofilter filled with wood chips was tested to treat ammonia emissions from a piggery located in Brittany (France). Two long-term tests ("summer" and "autumn" experiments) were carried out to improve biofilter applications for agriculture. The influence of climatic conditions on biofilter performance was taken into account. During summer 2012, the biofilter was operated for 74 days at different empty bed residence times (EBRTs) from 6 to 15 s. Inlet NH3 concentrations were relatively constant (around 15 mg m 3). Significant NH3 reductions were achieved at EBRT ¼ 12 s (removal efficiencies, RE, ranged between 90 and 100% for loading rates, LR, of around 4 g m 3 h 1). At a lower EBRT (6 s), RE dropped to roughly 30e50%. This was due to the dramatic increase in the loading rate (LR up to 12 g m 3 h 1) but the results showed that the change in atmospheric conditions (temperature and relative humidity) also had a significant influence on biofilter performance. It was evidenced that the use of a humidifier upstream of the biofilter must be taken into account for large-scale biofilter design, but only for specific conditions (the spraying of the biofilter having to be carried out exceptionally). During autumn 2012, the biofilter was operated for 116 days at EBRT ¼ 12 s. RE were around 80% for LR of around 3 g m 3 h 1. In such autumnal atmospheric conditions, a demister system should be installed upstream of the biofilter in order to avoid water accumulation in the bed material. Although biofiltration was suitable for NH3 treatment of piggery air, the need to control accurately the medium moisture content implies that biofilters would not be easily managed by a pig farmer

Traitement d’air de bâtiments d’élevage par biofiltration : estimation de la production de N2O liée au traitement de l’ammoniac NH3

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Traitement d'air de porcherie par biofiltration

International audienceA pilot-scale biofilter filled with wood chips was tested to treat ammonia emissions from a piggery located in Brittany (France). Two long-term tests ("summer" and "autumn" experiments) were carried out to improve biofilter applications for agriculture. The influence of climatic conditions on biofilter performance was taken into account. During summer 2012, the biofilter was operated for 74 days at different empty bed residence times (EBRTs) from 6 to 15 seconds. Significant NH3 reductions were achieved at EBRT = 12 s (removal efficiencies (RE) ranged between 90 and 100% for loading rates (LR) of around 4 g.m-3.h-1). At a lower EBRT (6 s), RE dropped to roughly 30-50%. This was mainly due to the dramatic increase in the loading rate (LR up to 12 g.m-3.h-1) but the results showed that the change in atmospheric conditions (temperature and relative humidity) also had a significant influence on biofilter performance. It was evidenced that the use of a humidifier upstream of the biofilter must be taken into account for large-scale biofilter design. During autumn 2012, the biofilter was operated for 116 days at EBRT = 12 s. RE were around 80% for LR of around 3 g.m-3.h-1. In such autumnal atmospheric conditions, a demister system should be installed upstream of the biofilter in order to avoid water accumulation in the bed material. Although biofiltration was suitable for NH3 treatment of piggery air, the need to control accurately the medium moisture content implies that biofilters would not be easily managed by a pig farmer

Earthworm effects on gaseous emissions during vermifiltration of pig fresh slurry.

International audienceTreatment of liquid manure can result in the production of ammonia, nitrous oxide and methane. Earthworms mix and transform nitrogen and carbon without consuming additional energy. The objective of this paper is to analyse whether earthworms modify the emissions of NH3, N2O, CH4 and CO2 during vermifiltration of pig slurry. The experiment used mesocosms of around 50 L, made from a vermifilter treating the diluted manure of a swine house. Three levels of slurry were added to the mesocosms, with or without earthworms, during one month, in triplicate. Earthworm abundance and gas emissions were measured three and five times, respectively. There was a decrease in emissions of ammonia and nitrous oxide and a sink of methane in treatments with earthworms. We suggest that earthworm abundance can be used as a bioindicator of low energy input, and low greenhouse gas and ammonia output in systems using fresh slurry with water recycling

Optimal transfer between extensive wastewater treatment systems combining vermifiltration, macrophyte lagoons and constructed wetlands.

communication oraleInternational audienc

Optimal transfer between extensive wastewater treatment systems combining vermifiltration, macrophyte lagoons and constructed wetlands.

communication oraleInternational audienc

Design of an integrated piggery system with recycled water, biomass production and water purification by vermiculture, macrophyte ponds and constructed wetlands

International audienceSince 2001 the swine experimental station of Guernevez has studied biological treatment plants for nutrient recovery and water recycling, suited to the fresh liquid manure coming out of flushing systems. An integrated system with continuous recycling was set up in 2007, associated with a piggery of 30 pregnant sows. It includes a screen, a vermifilter, and macrophyte ponds alternating with constructed wetlands. The screen and the vermifilter had a lower removal efficiency than in previous studies on finishing pigs. A settling tank was then added between the vermifilter and the first lagoon to collect the worm casts. A second vermifilter was added to recover this particulate organic matter. A storage lagoon was added to compensate for evaporative losses and complete pollution abatement, with goldfish as a bioindicator of water quality. The removal efficiency of the whole system was over 90% for COD and nitrogen, over 70% for phosphorus and potassium, and more than 4 logarithmic units for pathogens (E. coli, enterococci, C perfringens). Plant production was about 20 T DM ha-1 y-1. Floating macrophytes (Azolla caroliniana, Eichhornia crassipes, Hydrocotyle vulgaris) were more concentrated in nutrients than helophytes (Phragmites australis, Glyceria aquatica,y). Azolla caroliniana was successfully added to feed finishing pigs